Technical Field
The present invention relates to a continuously variable transmission control system for a vehicle having a continuously variable transmission device having a belt bridged between a driving pulley and a driven pulley and an electricity-driven actuator, and a control device that controls driving of the actuator.
Related Art
In the related art, a structure is known in which a belt type continuously variable transmission device is incorporated in a motive power transmitting mechanism that transmits motive power of a motive power source of a vehicle to a wheel. In the belt type continuously variable transmission device, a belt is bridged between a driving pulley on the side of the motive power source in the motive power transmission direction and a driven pulley on the side of the wheel. Of the driving pulley and the driven pulley, at least one pulley includes a fixed sheave and a moveable sheave which is moveable in an axial direction. As the belt type continuously variable transmission device, there is known an electrically-driven structure in which the moveable sheave is moved by an electricity-driven actuator.
JP H5-203005 A discloses a transmission device in which the fixed sheave of the driving pulley is fixed on a rotational shaft through which a torque of the motor is taken out, and the moveable sheave is placed to oppose the fixed sheave. A centrifugal weight is provided between a cam plate which rotates synchronously with the moveable sheave and the moveable sheave, and moves so as to move the moveable sheave toward the fixed sheave by an action of a centrifugal force.
In the structure described in JP H5-203005 A, because the centrifugal weight does not move so as to move the moveable sheave toward the fixed sheave until a rotational speed of the rotational shaft is increased to a predetermined speed, a reduction ratio in the transmission device is maintained at a constant. Because of this, even when the vehicle starts to move, a state of a high reduction ratio is maintained until a predetermined vehicle speed which is relatively high, and thus, there is still room for improvement from the viewpoint of improvement of the fuel consumption. In addition, in the structure of JP H5-203005 A, a degree of freedom in adjustment of the reduction ratio is low, and there is also room for improvement from the viewpoint of increasing the degree of freedom of setting the acceleration characteristic.
An advantage of the present invention is in the provision of a continuously variable transmission control system for a vehicle that can improve the fuel consumption of the vehicle to which the belt type continuously variable transmission device is incorporated, and which can also increase the degree of freedom of setting the acceleration characteristic.